Intensive works to develop new main battle tank began in the USA
after the end of MBT-70 program (Main Battle Tank of 70-ties) cooperated
with German Federation Republic in 1970. In year 1973 there was published US Armed
Forces competition for the best main battle tank's project. Competition won
"Chrysler" corporation with XM803 test tank in 1976. It's
developers paid great attention to crew safety and armament. Tank got indexation XM1
and after some improvements begun it's serial production named M1 "Abrams" in honor to General Abrams who commanded US forces in
Vietnam.

First serial M1 "Abrams" was produced
in February 1980 in Ohio state, Lima city, in US national tank plant.
Since 1982 tank was also built in Michigan state, Voren city "Detroit
Arsenal" tank plant. At the same time "General Dynamics"
corporation got license to built them. Till 1985 there were built 3 236
this type main battle tanks. Since 1986
to 1990 were built 840 tanks annually for US Ground Forces and in
year 1991 and 1992 there were produced 691 tanks for US Marine Corps.

Main battle tank has classic
arrangement with frontal drivers compartment. Hull and turret are welded
with multi-layered frontal armor similar to British armor "Chobhem".
Similarly to British main battle tanks "Chieftain" and
"Challenger", driver-mechanic with closed hatch is placed in
half-lying position. It allowed greatly incline frontal armed plate in
vertical inclination level such increasing defense from armor-piercing
projectiles. Driver-mechanic use motorcycle-type steering wheel connected
with automatic transmission.

M1 "Abrams" is armed
with M68E1 105-mm rifled gun (modified British L7 gun), fitted with
ejector and thermo sleeve body stabilized in two planes. Main gun is
placed in armored welded turret and is almost similar to main gun used on
M60. US specialists say that M1 twice surpassed M60 in overall characteristics.
Tank's commander and gunner are placed
right from main gun and loader - left. Main combat ammunition load (44
projectiles of 55) is placed is isolated rear turret's part. Access to
ammunition load is available only with opened armored screens. Other
ammunition storage is placed in armed containers placed in tank's body
(8) and in front of the loader (3).

Combat ammunition load
consists from M735 undercaliber wolfram head armor-piercing projectiles
with separating case, M774 and M883 with precipitant
uranium head as well. M737 is training projectile and is also used by M1
"Abrams".

Additional armament consists
from coaxial 7.62-mm machine gun, other the same caliber machine gun
placed in front of loaders hatch and 12.7-mm anti-aircraft machine gun
mounted on commanders observation turret. Tank's commander is able to use
it with closed hatch. Main battle tank is fitted with
thermo smoke equipment and 6 smoke grenade launchers, mounted on the turret
boards.

M1 "Abrams" has modern enough
main gun fire control equipment. There was published information that
"Abrams" defeated target in 1 850 m range from first shot, moving in
cross-country terrain with 40 km/h speed. Main sight used by gunner is
combined day-night optical device with built-in laser rangefinder and
sighting line stabilizer in vertical plane what allows to execute quiet
effective fire moving. Tank is also fitted with additional telescopic
device. Tank's commander is able to see gunner's sight view, which
allows making battlefield observation and sighting at once. M1
"Abrams" is able to notice tanks in 3 000 km range at night and
in 1 200 in fog. Commander is
equipped with periscope anti-aircraft machine gun's sight and six
observation blocks in turrets perimeter with 360-degree view.

M1 "Abrams" became
first western main battle tank fitted with gas turbine engine. First world
main battle tank fitted with such engine was T-80, entered service in
Soviet Armed Forces in 1976. M1 "Abrams" is fitted with AGT-1500
"Avco Lycoming" company engine which has 1 500 h.p. in 3 000
rate/minute. Engine is multi-fuel and uses kerosene, diesel and petrol.
Engines service life till major repairs is 1 800 hours or 19 000 km while tank diesel
engines serve only 600 - 900 working hours.

M1 "Abrams" has
hydromechanic transmission made in one block with engine and has four
forward and two backward gears. Tank turning radius is changing using
consistent hydro changeable gear in turning mechanism. Chassis has 7
rubber laid bearing rolls, two track supporting bearings, leading and
tracking wheels from each side. Main battle tank uses track with
rubber-metallic hinge and full-rubber tracks. Monotorsion suspension with
adjustable clearance allows changing bearing rolls dynamic clearance in
381 mm and full in 581 mm. Chassis and hulls boards are covered with anti-cumulation
screens.

M1 main battle tank has high
power to tone ratio in 28 h.p./twhat
determines high mobility. Tank has maximum road speed in 72 km/h and
cross-country - about 55 km/h. Moving
from stop position it reaches 30 km/h speed in 6.2 s. It is able to
overcome 30 degrees elevations, 1.24 m vertical steps, 2.77 m trenches and
fords unprepared 1.2 m water obstacles.

Main battle tank is equipped
with Nuclear, Biological, and Chemical mass defeating defense system,
which provides cleaned air to crew's face masks and increases
compartment's air pressure to prevent passing radioactive dust and
poisons. M1 "Abrams" is also fitted with radiological and
chemical reconnaissance equipment, fire prevention system, heater and
communication sources.

Developing main battle tank a
great attention caused technical maintenance and repairs simplifying
problems. For example engine can be changed in field conditions in 30
minutes, while the same operation in M60 lasted approximately 4 hours.

There were developed some M1 main battle tanks modifications. The first,
M1E1 was built in 1981. till 1985 there were built 894 such tanks. They
differed in 120-mm smoothbore gun and increased power projectiles.
In the end of 1986 new M1A1 modification entered service in US Armed
Forces. It had increased firepower and defense. Since 1991 begun
production of M1A2 differing from M1A1 in new thermovision sight, modernized
laser rangefinder, battlefield informational system, built-in dynamic
armor and modernized commanders observation turret.